kubernetes/kops · error

updating front-end for load-balancer %s: %w

Error message

updating front-end for load-balancer %s: %w

What it means

kOps wraps failures from `lbService.UpdateFrontend` when an existing Scaleway LB front-end must be reconciled (name, inbound port, or default backend) in RenderScw of LoadBalancerFrontend. The wrapped error comes from the Scaleway LB Zoned API.

Source

Thrown at upup/pkg/fi/cloudup/scalewaytasks/lb_frontend.go:144

		}
	}
	return nil
}

func (l *LBFrontend) RenderScw(t *scaleway.ScwAPITarget, actual, expected, changes *LBFrontend) error {
	lbService := t.Cloud.LBService()

	if actual != nil {

		_, err := lbService.UpdateFrontend(&lb.ZonedAPIUpdateFrontendRequest{
			Zone:        scw.Zone(fi.ValueOf(actual.Zone)),
			FrontendID:  fi.ValueOf(actual.ID),
			Name:        fi.ValueOf(actual.Name),
			InboundPort: fi.ValueOf(expected.InboundPort),
			BackendID:   fi.ValueOf(actual.LBBackend.ID),
		})
		if err != nil {
			return fmt.Errorf("updating front-end for load-balancer %s: %w", fi.ValueOf(actual.LoadBalancer.Name), err)
		}

	} else {

		frontendCreated, err := lbService.CreateFrontend(&lb.ZonedAPICreateFrontendRequest{
			Zone:        scw.Zone(fi.ValueOf(expected.Zone)),
			LBID:        fi.ValueOf(expected.LoadBalancer.LBID),
			Name:        fi.ValueOf(expected.Name),
			InboundPort: fi.ValueOf(expected.InboundPort),
			BackendID:   fi.ValueOf(expected.LBBackend.ID),
		})
		if err != nil {
			return fmt.Errorf("creating front-end for load-balancer %s: %w", fi.ValueOf(expected.LoadBalancer.Name), err)
		}

		expected.ID = &frontendCreated.ID

	}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Rerun `kops update cluster` after checking LB state in the Scaleway console
2. Validate InboundPort is in the allowed Scaleway range (e.g. 1-65535, not conflicting)
3. Verify the referenced backend still exists (BackendID from actual may be stale)
4. Check Scaleway credentials/permissions
5. Inspect the wrapped scw error code (409 conflict, 422 validation) and adjust the cluster spec accordingly

Example fix

// before: update without validating port
InboundPort: fi.ValueOf(expected.InboundPort),
// after: validate the port first
port := fi.ValueOf(expected.InboundPort)
if port < 1 || port > 65535 {
    return fmt.Errorf("invalid inbound port %d for front-end %s", port, fi.ValueOf(actual.Name))
}
InboundPort: &port,

// validate inputs before UpdateFrontend
port := fi.ValueOf(expected.InboundPort)
if port < 1 || port > 65535 { return fmt.Errorf("invalid inbound port %d", port) }
if fi.ValueOf(actual.LBBackend.ID) == "" { return errors.New("backend ID missing for frontend update") }
if _, err := lbService.WaitForLb(&lb.ZonedAPIWaitForLBRequest{Zone: zone, LBID: lbID}); err != nil { return err }

var serr *scw.ResponseError
if errors.As(err, &serr) && serr.Status == 404 {
    // frontend deleted concurrently: fall back to CreateFrontend path
}

When it happens

Trigger: RenderScw's update branch calls UpdateFrontend with FrontendID=actual.ID, Name, InboundPort=expected.InboundPort, BackendID; the API rejects — invalid InboundPort (privileged/out of range), backend ID stale, frontend deleted concurrently, auth/quota error.

Common situations: Changing the API-server port in the cluster spec to an invalid/in-use port; backend replaced between find and update (race); LB in transient state; credentials expired.

Related errors

• creating front-end for load-balancer %s: %w
• waiting for load-balancer: %w
• deleting load-balancer %s: %w
• updating back-end server IPs for load-balancer %s: %w
• creating back-end for load-balancer %s: %w

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/9d4af887f975b7d8. Report an issue: GitHub.